Flower Garden Banks National Marine Sanctuary hosts a spectacular variety of invertebrates (animals without backbones). Following are video highlights of various invertebrate activities observed in the sanctuary.
Hiding in Plain Sight
(video at top of page)
In this video, a Common Octopus (Octopus vulgaris) uses camouflage techniques to hide right out in the open at Stetson Bank. Can you find it? Once it realizes it has been spotted, it fluctuates between smooth and rough textures, but remains relatively motionless. It eventually gets concerned about the nearby divers and decides to move away from the camera, showing both its grace, size, and agility, all characteristics that aid in survival.
Be patient, it's worth the wait!
Video Length: 2:20
0:00-0:19 The camera moves towards a spot on the reef with small ridges and lots of algae, at Stetson Bank.
0:19-0:25 The camera focuses in on a Common Octopus (Octopus vulgaris) that is sitting perfectly still and mimicking the colors and textures of its surroundings.
0:25-0:38 The octopus stays in place but changes its body texture from rough to smooth and back again several times. It also moves just a bit as if trying to decide whether to stay or go.
0:38-1:00 The octopus continues to change texture and acts as if it's debating whether to face the diver or leave.
1:00-1:21 The octopus still seems to be debating between fight or flight options.
1:21-1:29 The octopus begins to slowly crawl away from the camera.
1:29-1:33 The octopus continues to move away, but also spreads out its arms to look bigger, and possibly more intimidating.
1:33-1:43 The octopus moves away, a little faster than before, then spreads its arms out even larger.
1:43-1:48 The octopus continues spreading out its arms and moving further across the reef.
1:43-2:09 The octopus begins moving more quickly away from the diver by gliding over the rocky terrain.
2:09-2:20 The octopus seems to finally decide that enough is enough and uses jet propulsion (squirting water out of its siphons) to swim away. It continues into the distance until you can barely see it.
Octopus & Squid
Octopus and squid belong to a class of animals called cephalopods, or head and foot animals. They are mollusks, but lack the external shells of their snail and clam cousins.
This video shows a Caribbean Two-spot Octopus (Octopus filosus) out hunting in broad daylight, which is rather an unusual occurrence.
The video begins with the octopus crawling and "jetting" (pushing itself forward by expelling a stream of water) across the reef with a file clam clasped in its tentacles. As the octopus flees the camera, it rapidly and repeatedly changes its color and pattern. Only in certain color combinations are the two spots visible that give it it's name. Outside of the den where the octopus disappears with its prey, you can see the leftovers of other file clams scattered about the reef. Piles of shell discards (middens), like these, often indicate where an octopus lives.
The end of this video shows brief clips of two small squid (probably Loligo plei) seen swimming up in the water column at night.
Video Length: 1:22
Moon Jellies (Aurelia aurita)
Jellies, like coral polyps, belong to the scientific group of animals known as Cnidaria (ni-day-ree-a). This video highlights the graceful, pulsing movements of moon jellies. Like coral, they may also provide shelter for other animals, as seen in the second half of the video. The small fish swimming under the moon jelly's bell are probably juvenile jacks.
Video Length: 0:35
While there are many different kinds of invertebrates found in a coral reef environment, they are not always easy to find. They tend to hide in the nooks and crannies of the reef as a means of avoiding predators, often venturing out after dark.
This video shows a variety of fascinating invertebrates found at Flower Garden Banks National Marine Sanctuary: banded coral shrimp feeding; slipper lobster crawling across the reef; decorator crab moving across the reef; file clam filtering water with shells open and tentacles extended; brittle star snaking its way across open coral polyps at night; slipper lobster crossing the flats at Stetson Bank; decorator crab crawling around between corals; close-up of a queen conch probing the sand with its proboscis; axiid lobster extending its gills outside its burrow; long-spine sea urchin waving its spines around amid a group of cardinalfish; banded coral shrimp snatching plankton; bristle worm crawling slowly cross a brain coral colony.
Video Length: 1:46
Credit: FGBNMS/Hickerson, Schmahl, Weaver
Sea Hares (Aplysia sp.)
Sea hares are often referred to as shell-less snails, although they do actually have small internal shells. The species in this video is relatively large, ranging up to 10 inches in length. Each sea hare has two pairs of rolled tentacles--a pair near the mouth, which it appears to use for feeding, and a pair called rhinophores on top of the head.
This video shows sea hares swimming over the algae-covered bottom at Stetson Bank by flapping the large, fleshy extensions of their mantles like wings. They were probably attracted to Stetson Bank because of all the algae, their primary food.
Video Length: 1:27